A nanowire is one of various semiconductor nanostructures and refers to a wire structure that has nanoscale dimensions. Generally, a nanowire includes a wire having a diameter of less than 10 nm to several hundred nanometers.
Methods for manufacturing such nanowires are divided into three major types.
First, there has been proposed a method in which a photoresist is patterned into nanoscale dimensions using an e-beam lithography apparatus, followed by etching silicon into nanoscale dimensions using the patterned photoresist as a mask, thereby manufacturing two-dimensional silicon nanowires.
However, such a conventional method for manufacturing silicon nanowires is unsuitable for mass production due to high fabrication costs.
Second, there has been proposed a vapor-liquid-solid (VLS) method which is a self-assembly method wherein a metal catalyst having nanoscale dimensions is formed, followed by introduction of a reaction gas (SiH4) while maintaining a high temperature of about 950° C., thereby growing two-dimensional silicon nanowires.
However, this method has difficulty in controlling a structure of nanowires and cannot control a direction in which silicon nanowires are grown.
Third, there has been proposed etching using a solution process. Etching using a solution process can provide reduction in time and cost, as compared with the self-assembly method. In the method for manufacturing silicon nanowires using a solution process, a hexagonal lattice pattern using nanostructures has been mainly used to precisely control geometric parameters (diameter, height, density, and the like) of silicon nanowires. However, it is difficult for this method to achieve individual control of parameters of the nanowires and to fabricate large-area nanowires.